Learning Goal: ESS3 - The origin and evolution of galaxies and the universe demonstrate fundamental principles of physical science across vast distances and time

Students demonstrate an understanding of the life cycle of stars by …

8a. Relating the process of star formation to the size of the star and including the interaction of the force of gravity, fusion, and energy release in the development of the star identifying and describing the characteristics common to most stars in the universe.

8b. Describing the ongoing process involves in star formation, their life cycles and their destruction

Students demonstrate an understanding of the origins and evolution of galaxies and the universe by...

5aa. Comparing the processes involved in the life cycle of stars (e.g. gravitational collapse, thermonuclear fusion, nova) and evaluate supporting evidence

What does this standard mean?

  • Stars are formed by the fusion of hydrogen into helium in their cores
  • Stars are classified on the Hertzsprung-Russell (H-R) Diagram by the relationship of their temperature and magnitude
  • Heat from fusion causes pressure and balances the attraction due to gravity to maintain a star’s formation
  • Stars evolve and change as the balance between the pressure and gravity changes
  • Stars begin as a large cloud of dust called a nebula
  • When the balance between pressure and gravity is lost the star core begins to contract creating giants, white dwarfs, and supergiants
  • When stars die their cores collapse creating a supernova explosion
  • Supernovas can create black holes or neutron stars
  • A star's life cycle varies depending on its mass


What prior knowledge do students need to know to understand the standard?
  • Properties of elements (hydrogen, helium)
  • Process of Fusion= lighter elements combining to create larger ones
  • Properties of Stars
    • Brightness of a star (Magnitude)
      • Apparent magnitude
      • Absolute magnitude
    • What factors control the brightness of a star
      • distance
      • size
      • internal heat
    • Properties of gravity
    • Color spectrum in relation to temperature
      • star spectral classes
        • temperature
        • color
      • properties of waves
        • wavelengths
          • longer wavelengths (Red)
          • shorter wavelengths (Blue)
  • Relationships between star color, temperature, mass, size, and age

What misconceptions might students have around the topics contained in the standard?
  • Think red stars are the hottest (red hot, blue cold)
  • Think massive stars may live longer than less massive ones
  • Think stars are fueled by the burning of gas
  • Think the brightness of a star depends on its distance

Unit Concept Map